Since the commit '91541b3' was applied, the declaration of function has
been removed from the 'region.h' header.
This patch fixes a following warning by including 'libds/region.h' from
'region.h'.
Change-Id: I59737e934aa95b535dba61b360ddca228dda5f7e
warning: implicit declaration of function 'ds_region_from_resource'
+#include "libds/region.h"
#include "region.h"
#include "compositor_private.h"
#include <stdlib.h>
+#include "libds/region.h"
#include "region.h"
#include "compositor_private.h"
#include <math.h>
#include <pixman.h>
+#include "libds/region.h"
#include "libds/log.h"
#include "util.h"